JPS5853533Y2 - temperature compensated camera system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a temperature-compensated camera system for detecting in advance the influence of environmental temperature during photographing and development, especially in instant photography.

Currently, there are two types of instant photography, in which the photo is completed on the spot it is taken: the beer-apart method, in which the positive print is peeled off from the negative layer after photographing and development, and the mono-sheet method, in which there is no need to peel off the positive print after photographing and development. has been put into practical use.

Both methods use sophisticated chemical reactions to form photographic images, and are easily affected by the environmental temperature at the time of photography and development. If this happens, the resulting photographic image will be very pale, and if the temperature is high (for example, outdoors in summer), it will become very dark, making it impossible to obtain a stable and satisfactory photograph.

Another type of instant photography utilizes different techniques, so that, contrary to the example above, the photographic image becomes very dark at low temperatures and very thin at high temperatures, resulting in a similarly stable and satisfactory photographic image. is not obtained.

The temperature of the instant photographic film itself changes depending on the environmental temperature, resulting in images that are too dark or too thin. The instruction manual shows the relationship between environmental temperature and development time.
Instructions are given to adjust the finish of the photographic image by changing the development time depending on the environmental temperature.

In addition, with the above-mentioned mono-sheet method instant photography, the instruction manual for the camera and film indicates the temperature range that can be used, and the camera's built-in photographic density control device (fractional control) is It instructs you to move it to adjust the final density of the photographic image.

Therefore, in order to obtain satisfactory instant photos,
It is necessary to know the temperature of the place where the photograph will be taken in advance, and then change the developing time and adjust the camera's contrast control device appropriately.

However, in reality, there is not always a thermometer available at the location where the photo is taken, and it is not known to what extent the shade control device should be adjusted appropriately at what environmental temperature, so a trial and error process is required. The reality is that after several attempts, you can get a photo that you are satisfied with.

It is truly uneconomical to have to take many shots through trial and error using expensive instant photographic film. The reality is that it requires a considerable amount of experience.

The present invention was developed to eliminate such conventional inconveniences, and it is possible to know the environmental temperature immediately before taking a picture and easily adjust the degree to which the camera's density control device is adjusted according to the environmental temperature at that time, without requiring any experience. The purpose is to make it possible to obtain instant photographs of satisfactory quality economically and easily under any environmental temperature.

In the present invention, in order to achieve this goal, a display window is opened on the back of the camera where a part of the film pack can be seen, and the temperature of the film pack in that environment can be seen. , Attach, apply or print a liquid crystal thermometer using reversible thermochromic material such as thermo tape, thermo label, thermo paint or thermotropic liquid crystal to the area corresponding to the display window of the camera. This problem is solved by providing an indicator of the gradation control device in addition to the usual gradation display as well as a display corresponding to the temperature obtained from the display window of the camera.

Furthermore, since the temperature of the film pack is measured, it can be used even if the film has just been taken out of the refrigerator.

To be more specific, on the back of the camera, for example, a 3X3C
A display window of about m is opened, and on the back of the film pack corresponding to this display window, for example, use thermo tape or a liquid crystal thermometer with various color-changing materials connected in sequence so that there are color-change points at 2°C intervals. For example, paste them together in a size of about 3 x 3 cm.

The temperature may be displayed by numbers or symbols indicating the temperature, by visually easy-to-understand patterns, or by using the changed color itself.

Display the same design as the thermo tape or liquid crystal thermometer display on which the film pack is attached on the indicator of the camera's contrast control device.

By doing this, you can measure the film (
Knowing the temperature of the film pack itself, the user can use this information to immediately adjust the camera's contrast control device without hesitation, eliminating failures in shooting due to temperature and trial and error in adjusting the contrast control device. It becomes possible to obtain satisfactory instant photographs.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIGS. 1 to 4 show an embodiment of a mono-sheet type instant photograph based on the present invention.

In FIG. 1, reference numeral 1 indicates a display window provided in a back cover portion 12 on the back side of a camera body 11 following a square cylindrical lens barrel 10.

This display window 1 is covered with, for example, a transparent acrylic plate, so that dust and dirt do not enter the inside of the camera, and the rear surface of the film pack P can be directly viewed.

In the figure, 16 is a shutter button, 13 is a finder, and 14 is an outlet for taking out instant photographic film after pressure processing.

In FIG. 2, numeral 2 indicates a liquid crystal thermometer sheet attached to the lower left portion of the back surface of a plastic film pack P containing unexposed instant photographic film.

Note that 15 indicates an outlet for instant photographic film.

Further, in FIG. 2, numeral 3 indicates a structural unit of the liquid crystal thermometer.

FIG. 3 shows a portion of the liquid crystal thermometer sheet 2 attached to the film pack P.

The liquid crystal thermometer sheet 2 is composed of a total of 18 thermotropic liquid crystals, 6, 8, 10, 12, 14,
16, 18, 20° 22.24.26.28, 30
, 32 , 34 , 36 , 38. At 40°C, the color changes to green, for example.

6.8,10.The liquid crystal that changes color at 12℃ is coated with liquid crystal so that it is displayed as A, as shown in the figure.
6.18. Liquid crystals that change color at 30, 32, and 34 degrees Celsius are displayed as B, and liquid crystals that change color at 22, 24, and 26.28 degrees Celsius are displayed as C. is displayed as D, and the liquid crystal that changes color at 36, 38, and 40°C is displayed as E.

FIG. 4 shows a grayscale control device F attached to the EE receiving section of the camera.

In the figure, reference numeral 4 indicates an EE light-receiving window, and a movable ring 5 for controlling the density is located outside of this window.

On the ring 5, in addition to a scale indicating the degree of density control, the same indications as A, B, C, D, and E on the liquid crystal thermometer sheet 2 attached to the back of the film pack P are also displayed.

6 indicates an index corresponding to the scale on the ring 5.

Therefore, the shading control device F of the camera can clearly have a temperature compensation function in addition to the original function of adjusting the shading of a photograph.

FIG. 5 shows a typical EE open circuit employing an electronic shutter equipped with a □density control device (fractional control) F.

In the figure, 7 indicates the power supply for the EE circuit, and 8 indicates the light receiving element Cds.
9 is a magnet for holding the shutter blade, R1 is a sliding resistor for adjusting the exposure level, Trl and Tr2 are transistors for controlling the shutter, and R2 is the transistor Tr. C indicates a load resistance, and C indicates a time constant capacitor.

The continuous optical wedge 8 is an ND filter made so that the transmittance changes continuously, and the sliding resistance R1 is adjusted in advance so that a constant amount of light on the image plane can be obtained at the intermediate position of the wedge 8.

The gradation control ring 5 provided around the EE light receiving window of the camera and the continuous optical wedge 8 are engaged with each other, and by moving the gradation control ring 5, the wedge 8 in front of the light receiving element Cds moves, and the light receiving element Cds The illuminance hitting the area changes.

Therefore, for example, in the case of an instant photographic film in which the image becomes lighter when the temperature is lower and the image becomes darker when the temperature is higher, the A and B sides (indicating low temperature) of the liquid crystal temperature display on the contrast control ring 5 should be set to the index 6. When combined,
If the wedge 8 has a high transmittance, it should cover the light receiving element Cds.

By doing this, the illuminance hitting the light receiving element Cds increases and the internal resistance of the light receiving element CdS becomes smaller, which shortens the time the shutter is open, and the contrast control ring 5
If the temperature is not adjusted (if the temperature is set to C, which indicates room temperature), the exposure will be underexposed and the photographic image will become darker.

Conversely, when the E side (indicating high temperature) is set to index 6, the wedge 8 with lower transmittance will cover the light receiving element Cds, the illuminance hitting the light receiving element Cds will decrease, and the light receiving element C
Since the internal resistance of the ds increases, the shutter remains open longer and the photographic image becomes fainter.

The photographer first looks at the display window 1 on the back cover 12 of the camera and selects which one of A, B, C, D, and E on the liquid crystal thermometer sheet 21 attached to the back of the film pack P.
Find out whether the color has changed (for example, it has changed to green) and check the A displayed on ring 5 of the camera's shade control device F.
, B, C, D, and E scales to index 6, the exposure is fixed and a satisfactory photograph can be easily obtained.

In other words, the photographer can use the film pack P even under various environmental temperatures.
Check the display on the back of the camera to control the intensity of the camera F.
Since all you have to do is adjust the scale, there is no need for the conventional trial and error, the associated uneconomical costs, and the need for extensive experience.
This makes it easier.

In the above embodiment, an example of a mono-sheet method has been described, but it is of course applicable to a beer-apart method as well.

Even when the developing time is changed depending on the environmental temperature in the beer apartment method, the display design of the thermometer sheet 2 may be provided on the developing timer display section attached to the well-known camera.

Further, in the above embodiment, in the thermometer sheet 3, 6,
8,10. Those that change color at 12℃ are A, 14, 16
, 18.

Those that change color at 20℃ are B, 22, 24, 26.28℃
Items that change color at C130, 32, and 34°C are shown as D, and items that change color at 36°, 38, and 40°C are shown as E.This system is used to display items that change color in blocks. It goes without saying that it is necessary to change the contents and combinations of block configurations, or to change the measurement range of the thermometer sheet used, depending on the characteristics of the degree of change in density with respect to the environmental temperature of the instant photographic film used.

Furthermore, which scale of the density control device F corresponds to which block of the thermometer sheet 2 may be determined depending on the characteristics of the instant photographic film.

It is also possible to provide a temperature display material that changes depending on the temperature near the film pack of the camera body, but since the display material needs to measure the temperature of the film itself, it is necessary to place it inside the camera and store the film. Providing it in the cassette will most accurately indicate the temperature of the film.

[Brief explanation of drawings]

Figure 1 is a rear perspective view of a camera employing the system of the present invention, and Figure 2 is a rear perspective view of a film pack. Fig. 3 is a plan view of the liquid crystal thermometer sheet, Fig. 4 is a plan view showing the light receiving window and shade control part of the camera, and Fig. 5 is an EE
There is an open circuit. K...Camera, P...Film pack, F...Density control device, 1...
・Display window, 2...LCD thermometer sheet, 3.
...Constituent unit of liquid crystal thermometer.

Claims (1)

[Scope of utility model registration request] A film pack or camera containing unexposed film affixed, coated or printed with a material whose color or density changes reversibly with temperature so that it can be observed from outside the camera, and instructions based on changes in color or density of the material. A temperature-compensated camera system is used to manually control the resulting density of the photograph.